Field of the Invention
The present invention relates to spectroscopy and more specifically, the present invention relates to an ATR/FTIR spectroscopic system and method that can also automatically provide different contact pressures while providing timed delay capabilities as a beneficial feature.
Description of Related Art
Attenuated total reflectance (ATR) is an optical interrogation technique often used in conjunction with infrared spectroscopy (e.g., Fourier Transform Infrared (FTIR)), which enables samples to be examined directly in a solid, liquid or a gas state. In particular, ATR capitalizes on total internal reflected light produced at the interface of a configured internally reflecting element (IRE) and a coupled sample plane. In operation, a beam of light (e.g., infrared) is passed through the IRE crystal in such a way that it reflects at least once off of the internal surface in contact with the sample. This reflection forms an evanescent wave which extends into the sample, often up to about 2 microns, with the exact value being determined by the wavelength of light, the angle of incidence and the indices of refraction for the IRE crystal and the sample medium being interrogated. The reflected beam, which carries the spectral information of the sample, is thereafter interrogated for analysis via, for example, a single pixel, linear array or 2 dimensional array detector.
As generally alluded to above, the samples, primarily the solid samples to be interrogated using ATR as the investigation technique, can come in the form of many different shapes and sizes. In order to enable efficient optical coupling, a force must be applied to such samples with a configured stage mechanism that is designed to provide intimate contact with an optical component, such as a Diamond, Silicon, or Germanium (Ge) ATR element. Conventional stages include pressure mechanisms that include mechanical screws, levers, slides, and actuators that are designed to apply compressive forces on a given sample.
However, while a pressure mechanism is required to compress the sample tightly against the desired ATR element surface to enable intimate contact, it is to be noted that in some cases, applying such force with speedily and repeatably with conventional means can be difficult for the person operating the instrument.
Accordingly, the present invention is directed to providing a compact ATR/FTIR optical instrument that is configured to provide different contact pressures to preferred samples as part of the operation. In particular, the present invention includes controlling the contact force being applied to any material and with an additional novel feature of a time delay (interval) means to allow the user to be positioned at a remote location during operation.